2580961F_MSW_GTF/GTF-Xtra_07-2018_ENG
FEEDBACK MODES
The GTF has the following power control modes:
V-voltage
V
2
-squared voltage
I-current
I
2
-squared current
P-power
A control mode is enabled with parameter Hd.6.
Voltage feedback (V)
To keep voltage on the load constant, this compensates possible variations in line voltage with reference to the rated voltage
saved in riF.V. (expressed in Vrms).
The voltage value maintained on the load is (ref.V*P%_pid_man/100) and is indicated in the Modbus 108 register.
Voltage feedback (V
2
)
To keep voltage on the load constant, this compensates possible variations in line voltage with reference to the rated voltage
saved in riF.V. (expressed in Vrms).
The voltage value maintained on the load is (rif.V*
V (P%_pid_man/100)), and is indicated in the Modbus 108 register.
Current feedback (I)
To keep current on the load constant, this compensates possible variations in line voltage and/or variations in load impedance
with reference to the rated current saved in riF.I. (expressed in Arms).
The current value maintained on the load is (rif.I*P%_pid_man/100), and is indicated in the Modbus 108 register.
Current feedback (I
2
)
To keep current on the load constant, this compensates possible variations in line voltage and/or variations in load impedance
with reference to the rated current saved in riF.I. (expressed in Arms).
The current value maintained on the load is (rif.I*
V (P%_pid_man/100)), and is indicated in the Modbus 108 register.
Power feedback P
To keep power on the load constant, this compensates both variations in line voltage and variations in load impedance with
reference to the rated power saved in riF.P. (expressed in kWatt).
The current value maintained on the load is (rif.P*P%_pid_man/100), and is indicated in the Modbus 108 register.
IMPORTANT!
Feedback calibration can be activated from the digital input (parameters DIG and DIG.2) or by serial control (ref. bit15) and, IF
DEMANDED, IT MUST be activated only with Hd.6=0 (the required Hd.6 value can be set only after calibration) and preferably
with maximum power on the load (ex. P_man or P_pid 0 100%).
If you change function mode (PA, ZC, BF, HSC), you have to re-run the Feedback calibration procedure.
For non-linear loads (ex.: Super Kanthal or Silicon Carbide) the automatic calibration procedure IS NOT necessary. Set the
value of parameters ref.V, ref. I, ref. P based on the specic nominal of the load shown on the data-sheet.